Power interruption control system

ABSTRACT

Where a plurality of processing operations are powered from a common electrical supply, shutdown of the operations by momentary interruptions of power is prevented by timing a main circuit relay not to open unless the interruption has a preselected time duration, shorting individual switches that have opened due to the interruptions, and breaking such shorts soon after the power has resumed.

United States Patent George D. Bernhard Lincoln Park;

Olek Schwarz, Plainfield, NJ. 861,882

Sept. 29, 1969 May 4, 1971 Anaconda Wire and Cable Company lnventorsAppl. No. Filed Patented Assigne'e POWER lNTERRUPT ION CONTROL SYSTEM 4Claims, 3 Drawing Figs.

Int. Cl 1101b 47/18 Field of Search 317/22, 36

[56] References Cited UNITED STATES PATENTS 2,934,701 4/1960 Weisberg etal. 317/141X 3,350,581 10/1967 Stein 3l7/141X 3,366,848 1/ 1968 Luehringet al..' 3 l7/22X Primary ExaminerJames D. Trammell Attorney-Victor F.Volk ABSTRACT: Where a plurality of processing operations are poweredfrom a common electrical supply, shutdown of the operations by momentaryinterruptions of power is prevented by timing a main circuit relay notto open unless the interruption has a preselected time duration,shorting individual switches that have opened due to the interruptions,and breaking such shorts soon after the power has resumed.

PMENiTE unn 4m: 3577.034

- INVENTORS.

v I VGEORGE BERNHARD OLEK SCHWARZ Mill 1 POWER INTERRUPT ION CONTROLSYSTEM BACKGROUND OF THE INVENTION vln certain processing operations,particularly operations involving the continuous processing of anadvancing strand, interruptions ofpower present a serious problembecause, if the operation is merely resumed, without inspecting thecondition of strand, after a lengthy interruption, portions of thestrand will be damaged due to excessive exposure to processingconditions and to the sagging of the strand upon the slowing down oftakeup devices. In many processes it is necessary to maintain acontrolled strand tension, and if the takeup devices are started withslack strands these devices will overspeed and cause the strand to snapwhen the slack has been taken up. For this reason it has been thepractice to have a manual control of the startup of each suboperation ina strand processing plant after a power shutdown. We have found,however, that the great majority of power interruptions are so short,less than 30 cycles of a 60 Hz. power supply, that automatic resumptionof operations may safely proceed, without damage, while the economiclosses due to a high frequency of shutdowns, each requiring a manualstartup, are severe.

The mere introduction of a timing device to prevent the opening of powercircuits during very short power interruptions does not solve theproblem, however, since each of many suboperations must have its ownpower control that opens when the power is interrupted. The reason forthe individual controls is that the restart can then be manuallyoperated in the event that the interruption continues too long. Where,for

example, a large plurality of strands are being processed, each' of thespindle clutches for taking up the strands must be in dividuallyrestarted after a long shutdown, and for this reason relays must beprovided that will hold the individual circuits open after the powerfails. Unfortunately, in the absence of prohibitively expensive hardwarefor each subprocess, these circuits have necessarily remained open aftershort interruptions even though the main circuit has not opened, so thatthe benefits of the timing device could not be realized.

SUMMARY In an electrical power supply system for an operation comprisinga plurality of suboperations each requiring a supply of electric power,where the suboperations are subject to malfunction upon automaticrestart after a shutdown of sufficient duration, we have invented theimprovement comprising a first timer relay means comprising switchmeans, with the timerrelay means closing the switch means a preselectedbrief time following the energizing of the timer relay means, the switchmeans opening essentially without delay upon the deenergizing of thetimer relay means. Our improvement also comprises a second timer relaymeans comprising switch means, with the timer relay means opening theswitch means a preselected brief time following the deenergizing of thesecond timer relay means, the switch means closing essentially withoutdelay upon the energizing of the second timer relay means.

In addition, our improvement comprises a first switching relay meanscomprising a switch means that is normally open and controls the currentto a plurality of the suboperations and is itself controlled by theswitch means of the second timer relay means, and also comprises aplurality of pushbutton means, a like plurality of local relay means andanother like plurality of normally closed, remotely controlled switchmeans, each of the local relay means comprising a local switch means,each of the local switch means being normally open and controlling, inparallel with one of the pushbutton means and one of the remotelycontrolled switch means, the energizing of its associated local relaymeans and one of the suboperations, and being itself controlled by theswitch means of the second timer relay.

Finally our improvement comprises gang relay means conthe first timerrelay, whereby, upon the interruption of power for a period of time notexceeding the preselected time setting of the second timer relay means,the suboperations will resume without activation of the pushbuttonmeans, and upon the interruption of power for a period of time exceedingsaid preselected time setting, and the resumption of power, each of thesuboperations will start without delay upon, and only upon, theactivation of its associated pushbutton means.

Our invention has particular application where the suboperationscomprise the processing of strands and the interruption of power wouldcreate an accumulation of slack in the strands, and where the powersupply is 60 Hz. and the preselected time for the second timer relaymeans is about 30 cycles.

We have invented the method of controlling the electrical power for aplurality of suboperations from a common electrical supply to avoidshutdown during very brief power interruptions, by the steps of timing amain circuit that feeds power to all the suboperations so that itremains closed for a preselected brief period of time after powerfailure, opens upon the expiration of the time period, and closes againessentially without delay upon the resumption of power. Our methodcomprises the steps of opening a first switch in each of thesuboperations when the power fails, automatically closing a secondswitch that short circuits the first switch in each of the suboperationswhen the power fails and simultaneously, automatically opening each ofthe second switches again after, and only after, a preselected timeperiod following the resumption of power, thereby providing time for theactivation of the reclosing of the first switches.

BRIEF DESCRlPTlON OF THE DRAWlNG HO. 1 shows an idealized side view of asuboperation using our invention.

FIG. 2 shows a diagram of a controlling circuit of our invention.

FIG. 3 shows a diagram of circuits controlled by the circuit of F IG. 2.

DETAILED DESCRIPTION OF A PREFERRED EMBODlMENT Referring first to FlG. 3a main power supply 9 is the sole electrical supply line for anoperation 10 that comprises a large number of suboperations of whichsuboperations 11, 12, 13 are represented in FIG. 3. ln the embodimentdescribed these suboperations comprise the activation of a solenoid 14(F IG. 1) of a clutch 15 that brings an idler roll 16 into engagementwith drive wheel 17, powered by a motor 18, and driven wheel 19 mountedto rotate a takeup spool 21 for a strand 22 being processed by an ovenor other apparatus 23, of which many kinds are known for which thepresent invention has application. If there is an interruption in thesupply 9 the motor 18 will, of course, stop and the clutch 15 willdisengage. When the motor 18 stops the spool 21 will also soon stop but,because of the inertia of the various elements of the processingoperation, such as a large payoff reel 24 from which the strand is beingsupplied, strand will continue to feed through the process for awhileand form a slack loop upstream of the spool 21. The motor 18 operates ata preselected torque to keep a proper tension in the strand and if themotor and clutch should reengage automatically upon the resumption ofpower after too much slack strand had accumulated, the motor would raceand the spool 21 pick up sufficient speed to snap and damage the strand22 when the slack was all taken up. For this reason and also to provideoperator control over the initial start up of the operation,suboperation 11 is protected by a relay 26 and its associated switch 27which is normally open and closes only when current passes through thecoil of the relay 26. Since the switch is in series with the coil theenergizing of the circuit has the effect of locking in the relay 26 andits switch 27 in the usual manner. Upon start up this energization isaccomplished by manually operating a pushbutton 28.

Power for the operation'lo is supplied from a transformer 19 through anormally open switch 31 that is associated with a relay coil 32 (FIG. 2)in a circuit energized from the supply 9 by a transformer 33. A timerrelay 34 having an associated normally open switch 36 with which therelay coil is in series and which is parallel to a pushbutton 37 isenergized from the transformer 33. For the timer relay 34 we prefer touse Agastat Timing Relay Model 2422AA, obtainable from the AgastatDivision of the Elastic Stop Nut Corporation of America, Elizabeth, N.I. When the supply circuit opens, the timer relay 34 delays 30 cycles ofthe 60 cycle power current before opening the switch 36 but when powerreturns to energize the relay coil the switch closes without anyappreciable delay. Thus if there is an interruption in the power supplythat is briefer than 30 cycles the switch 36 will not open at all andwhen the current resumes it will pass through the coil 32 and close theswitch 31 thus supplying power to all the suboperations ll, 12, 13 etc.If, however, the interruption lasts for longer than 30 cycles, uponresumption the switch 36 will be open and current will not flow throughthe relay 32 until the pushbutton 37 is contacted manually. In additionto the timer relay 34 we have provided a timer relay 38 such as AgastatTiming Relay Model 24l2AA with an associated switch 39 in series with arelay 41. The switch 39 is normally open and opens without delay whenthe coil of the relay 38 is deenergized. When the coil of the relay 38is reenergized, however, the switch does not close immediately but isdelayed for some preselected period of time from 10-30 cycles determinedby considerations herein below explained The relay 41 is associated witha plurality of normally closed switches 42 in parallel with thepushbuttons 28 and switches 27. When the power is on and thesuboperations ll, 12, 13 are proceeding normally the switches 36, 39,31, 27 are closed and the switches 42 are open. Upon a power failure theswitches 39, 31, and 27 open immediately, the switch 36 and the switches42 close immediately and the switch 36 remains closed for 30 cycles. [fpower is resumed within the 30 cycle time period the switch 36 does notopen at all so that the resumption of power energizes the relay 32,closing switch 31, and since the switches 42 have been closed, energizesthe relays 26 to close the switches 27 so that each of the suboperations11, 12, 13 is able to continue without manual control. The motors 18start, the clutches l engage and the spools 21 take up wire which hasnot been slackened sufficiently to be damaged. After the power has beenresumed for from to 30 cycles the timer relay 38 closes the switch 39,energizing the relay 41 to reopen the switches 42. The delay time forthe timer relay 38 need be only sufficient to permit the relays 26 toclose the switches 27 before the switches 42 are reopened.

In the event that a power interruption exceeds the 30 cycle duration,and then resumes, the current will find the switch 36 open andconsequently the switch 3] will remain open until the pushbutton 37 iscontacted manually. Even after such contact both switches 27 and 42 willbe open, the switch 42 having opened shortly after power was resumed,and none of the suboperations will be energized until the pushbuttons 28are contacted, whereupon the switches 27 will close. Signal lamp 42 andindividual stop pushbuttons 43 are conventional.

ln the electrical supply system described for the operation 10 theplurality of suboperations 11, l2, 13 each require the supply 9 ofelectric power and are subject to malfunction due to slacking of thewire 22 after a shutdown of sufficient duration, such as one muchexceeding 30 cycles. In our improvement the first timer relay means 38closes the first switch means 39 a preselected brief time following theenergizing of the timer relay 38, but the switch 39 opens essentiallywithout delay upon the deenergizing of the relay 38. A second timerrelay means 34 comprises the second switch means 36 that closesessentially without delay when the means 34 is energiled- The firstswitching relay means 32 comprises a third switch means 31 which isnormally open and controls the supply of electric current to theplurality of suboperations 11, l2, 13. The second switch means 36controls the current energizing the first switching relay means 32. Oursystem comprises the plurality of pushbutton means 28, like plurality oflocal relay means 26 and like plurality of normally closed, remotelycontrolled switch means 42, with each of the local relay means 32comprising a local switch means 27 that is normally open and controls,in parallel with one of the pushbuttons 28 and one of the switches 42,the energizing of one of the suboperations, such as suboperation 11, andis itself controlled by the switches 42. The energizing of this gangrelay is controlled by the first switch means 39 so that upon theinterruption of power for a period of time not exceeding 30 cycles thesuboperations 11, 12, 13 will resume without activation of thepushbuttons 28, and, upon the interruption of power for a period of timeexceeding 30 cycles, and the resumption of power, each of thesuboperations 11, 12, 13 will start only upon the activation of itsassociated pushbutton 28.

We claim:

1. In an electrical power supply system for an operation comprising aplurality of suboperations each requiring a supply of electric power,said suboperations being subject to malfunction upon automatic restartafter a shutdown of sufficient duration, the improvement comprising:

A. first timer relay means comprising first switch means, said timerrelay means closing said switch means a preselected brief time followingthe energizing of said timer relay means, said switch means openingessentially without delay upon the deenergizing of said timer relaymeans,

B. second timer relay means comprising second switch means, said secondtimer relay means opening said second switch means a preselected brieftime following the deenergizing of said second timer relay means, saidsecond switch means closing essentially without delay upon theenergizing of said second timer relay means,

C. a first switching relay means comprising a third switch means, saidthird switch means being normally open and controlling the supply ofelectric current to a plurality of said suboperations, said secondswitch means controlling the current energizing said first switchingrelay means,

D. a plurality of pushbutton means, a like plurality of local relaymeans, and a like plurality of normally closed, remotely controlled,switch means, each of said local relay means comprising a local switchmeans, each of said local switch means being normally open andcontrolling, in parallel with one of said pushbutton means and one ofsaid remotely controlled switch means, the energizing of its associatedlocal relay means and one of said suboperations, and being itselfcontrolled by the switch means of said second timer relay means, and

E. gang relay means controlling said remotely controlled switch means,energizing of said gang relay means being controlled by said firstswitch means whereby, upon the interruption of power for a period oftime not exceeding the preselected time setting of said second timingrelay means, said suboperations will resume without activation of saidpushbutton means, and, upon the interruption of power for a period oftime exceeding said preselected time setting, and the resumption of saidpower, each of said suboperations will start only upon the activation ofits associated pushbutton means.

2. The system of claim 1 wherein said suboperations comprise theprocessing of strands and the interruption of power creates anaccumulation of slack in said strands.

3. The system of claim 1 wherein said power supply is 60 Hz. and saidpreselected time for said second timer relay means is about 30 cycles ofsaid supply.

4. The method of controlling the electrical power for a plurality ofsuboperations from a common electrical supply to avoid shutdown duringvery brief power interruptions, comprising the steps of:

A. timing a main circuit-feeding power to all of said suboperations toremain closed for a preselected brief period of time after powerfailure, to open upon the expirationof C. automatically Closing a secondswitch short circuiting said period, and'to close againessentially-without delay D. simultaneously automatically opening eachof said Upon the resumption f P i a second switchesafter, and onlyafter, a preselected period B' P a Switch in each of Said suboperafiqnsof time following the resumption of power, thereby power I providingtime for activation of the closing of said first said first switch ineach of said suboperations upon said Swnches' power failure,

1. In an electrical power supply system for an operation comprising aplurality of suboperations each requiring a supply of electric power,said suboperations being subject to malfunction upon automatic restartafter a shutdown of sufficient duration, the improvement comprising: A.first timer relay means comprising first switch means, said timer relaymeans closing said switch means a preselected brief time following theenergizing of said timer relay means, said switch means openingessentially without delay upon the deenergizing of said timer relaymeans, B. second timer relay means comprising second switch means, saidsecond timer relay means opening said second switch means a preselectedbrief time following the deenergizing of said second timer relay means,said second switch means closing essentially without delay upon theenergizing of said second timer relay means, C. a first switching relaymeans comprising a third switch means, said third switch means beingnormally open and controlling the supply of electric current to aplurality of said suboperations, said second switch means controllingthe current energizing said first switching relay means, D. a pluralityof pushbutton means, a like plurality of local relay means, and a likeplurality of normally closed, remotely controlled, switch means, each ofsaid local relay means comprising a local switch means, each of saidlocal switch means being normally open and controlling, in parallel withone of said pushbutton means and one of said remotely controllEd switchmeans, the energizing of its associated local relay means and one ofsaid suboperations, and being itself controlled by the switch means ofsaid second timer relay means, and E. gang relay means controlling saidremotely controlled switch means, energizing of said gang relay meansbeing controlled by said first switch means whereby, upon theinterruption of power for a period of time not exceeding the preselectedtime setting of said second timing relay means, said suboperations willresume without activation of said pushbutton means, and, upon theinterruption of power for a period of time exceeding said preselectedtime setting, and the resumption of said power, each of saidsuboperations will start only upon the activation of its associatedpushbutton means.
 2. The system of claim 1 wherein said suboperationscomprise the processing of strands and the interruption of power createsan accumulation of slack in said strands.
 3. The system of claim 1wherein said power supply is 60 Hz. and said preselected time for saidsecond timer relay means is about 30 cycles of said supply.
 4. Themethod of controlling the electrical power for a plurality ofsuboperations from a common electrical supply to avoid shutdown duringvery brief power interruptions, comprising the steps of: A. timing amain circuit-feeding power to all of said suboperations to remain closedfor a preselected brief period of time after power failure, to open uponthe expiration of said period, and to close again essentially withoutdelay upon the resumption of power, B. opening a first switch in each ofsaid suboperations upon said power failure, C. automatically closing asecond switch short circuiting said first switch in each of saidsuboperations upon said power failure, D. simultaneously automaticallyopening each of said second switches after, and only after, apreselected period of time following the resumption of power, therebyproviding time for activation of the closing of said first switches.